The animal involved is the biggest killer whale in captivity and has a track record of deadly interactions with humans.

That size and history are so significant, SeaWorld doesn't let its trainers into the tank to interact with it.

"[The trainer] was on the side of the deck, rubbing the animal down, when he just pulled her down under the water. She drowned," Sea World's zoological curator Chuck Tompkins told 10 Connects late Wednesday night.

Tompkins says he doesn't know why the animal attacked but he does know about the animal's past; it has been involved in two other human deaths.

"Due to those incidents and his size, we do not get into the water and interact with this animal," said Tompkins.

The animal happens to be the largest orca in captivity, at more than 22 feet long and 12,300 pounds. Tilikum, or Tily for short, is double the size of the other whales at the park. Shamu is the stage name for all of SeaWorld's killer whales.

SeaWorld says the theme park's trainers have had thousands of safe interactions with Tily, including the very trainer who lost her life on Wednesday.

Dawn Brancheau, 40, has more than a decade of killer whale training under her belt. In fact, Brancheau was the most experienced in this Sea World family, with 16 years at the park.

"I can't put it into words how we are all feeling. I, for one, lost a sister," said Tompkins.

Brancheau had worked her way into a leadership role at Shamu Stadium after spending more than a decade working with killer whales. She was inspired by a trip to SeaWorld when she was nine years old.

Officials are treating this as an accidental death, and called the incident a drowning.

"The trainer was explaining different things about the whale... and then the trainer that was down there walked away from the window, and then [the killer whale] took off really fast in the tank and he came back, shot up in the air, grabbed the trainer by the waist and started thrashing [her] around," Biniak said.

Killer whale expert Nancy Black said the animal could have been playing and the incident could have been an accident.

"They are very intelligent creatures. They have emotions and feelings. Maybe it was unhappy in the situation, maybe it was bored," Black said.

Lerato Molewa said before the incident, a trainer told her the whale had been acting agitated. "He really explained to us that, you know, people have moods changing," Molewa said.

"Sometimes you fight with your sister, you can fight with your brother. So one of the whales is not doing good at all ... we saw it. It was running like, miserably. We could tell. We could tell this whale was not in a good mood at all."

Park officials deny anything was wrong with Tily until the moment the killer whale pulled Brancheau into the water.

People for the Ethical Treatment of Animals blasted SeaWorld in a blog post, and PETA called on the park to replace its animals with robotic lookalikes.

Out of respect for the family, all whale shows are suspended until further notice at SeaWorld parks.

"First things first, we have to re-evaluate our safety procedures in dealing with these animals," said Tompkins of Sea World.

The same goe for Sea World in San Diego, according to David Koontz, a spokesman. Koontz says he doesn't know when the show will resume.

Same orca involved in other deaths

Tilikum has been previously connected to two other human deaths. He was one of three whales blamed for killing a trainer in 1991 at Sealand of the Pacific in Victoria, British Columbia.

A man's body was also found draped over Tilikum at SeaWorld Orlando in July 1999. Daniel Dukes reportedly made his way past security at SeaWorld and either jumped, fell or was pulled into the frigid water of Tilikum's huge tank.

An autopsy ruled that he died of hypothermia, but authorities said it appeared Tilikum bit the man and tore off his swimming trunks.

Other killer whale attacks have occurred in SeaWorld parks.

In November 2006, trainer Kenneth Peters, 39, was bitten and held underwater several times by a 7,000-pound killer whale during a show at SeaWorld's San Diego park. He escaped with a broken foot.

The 17-foot-long orca who attacked him was the dominant female of SeaWorld San Diego's seven killer whales. She had attacked Peters on two prior occasions, in 1993 and 1999.